Hot-air furnace



May 14, 1929.

J. J. GREFENSTETTE now AIR mumps 2 Sheets-Shed Filed 'June 1 192'? y 14, 1929- J. J. GREFENSTETTE 1.712.699

HOfI' AIR FURNACE Filed June 14, 1927 ZSheets-Sheet 2 gmxmtoc JJ a a/( 2225522558.

IIIIIIIIIII.

Patented May 14, 1929.,

UNITED STATES JOHN J. GREFENSTET'I'E, 0F TOLEDO, OHIO.

HOT AIR, FURNACE.

Application filed June 14,

The present invention. is directed to improvements in hot air furnaces.

The primary object of the invention is to provide a furnace wherein a series of bafiie plates are mounted in vertical spaced relation in the fire pot thereof in order that the heat from the burner will be directed against the inner surface of the fire pot wall to cf fectively heat the same, whereby the fresh air will bethoroughly heated.

Another object of theinvention is to pro vide battle plates so constructed that they can be conveniently placed in the fire pot of a furnace already installed as an attachment therefor.

In the accompanying drawings:

Figure 1 is a vertical, sectional view through a furnace, showing the battle plates in the fire pot thereof.

Figure 2 asectional view on line 2-2 of Figure l.

Figure 3 is a transverse sectional view through a pot, showing a modified form of support for the baffle plates.

Figure is a sectional view on line dl of Figure 3.

Referring to the drawings, 1 designates the outer casing and 2 an inner casing, which, in the type of furnace shown, provides a fresh air inlet space 3 which communicates with the space 4- defined by the wall of the lire pot 5and the hood 6. It will be obvious that the fresh air passing through the space 4: will be subjected to heat'radiating from the wall of the fire pot. v

The fire pot is of a conventional type and into which is directed the heat generated by the gas burner 7.

In order that the flame and heat from the burner will be directed against the inner surface of the fire pot 5 to effectively heat the same a plurality of baflle plates 8 are pro vided, the peripheries of which are spaced from the fire pot wall to permit passage of the flame and heat.

The baffle plates are formed from a plurality of semi-circular sections 9 and 10, in order that they may be conveniently passed through the door opening, not shown,

, disposed in overlapped relation anc 1927. Serial No. 198,788.

of the furnace, in order be installed in a furnace already in use. Each section is provided with a pair of openings 11 for reception of the tie rods 12, four of which are used. The lower ends of the tie rods engage upon the upper ends of the pedestals 13, the lower ends of said pedestals resting upon the foundation 14. Spacing sleeves 153 are engaged upon the rods between the baffle plates and serve to maintain the battle plates in vertical spaced relation, the lowermost baffle plate being engaged upon the collars 16 of the pedestals. The sections 9 and 10 after being engaged upon the rods 12 have their straight sides retained thus by clan'iping bolts 17. The uppermost baliie plate is connected with the adjacent baffle plate by relatively short tie rods 18, and maintained spaced therefrom by sleeves 19.

In Figures 3 and 4, the fire pot is shown equipped with a pair of lugs 20 which support baffle plates 21 which are also formed from sections 22 and 23, the sections 23 being hingedly connected to the fire pot wall, as at 24-. These sections are also connected in overlapped. relation by clamping bolts 25 and are used in connection with lire boxes especially equipped for the installation of the bail-1e plates by the provision of the lugs 20. "Having thus described the invention, I claim The combination with the fire pot of a furnace, of a plurality of pedestals mounted therein and provided with collars, a plurality of vertically spaced inpervious bafiie plates located coaxially with the walls of the lire pot, each baiile plate consisting of a pair of sections having their inner edges overlapped, means for securing the overlapped edges, tie rods passing through the sections and having their lower ends resting upon the pedestals, and sleeves engaged upon the tie rods and disposed between the baflie plates, the lowermost bafiie plate resting upon said collars as and for the purpose set forth.

" In testimonywhereof I aflix my signature.

JOHN J.'GREFENSTETTE. [n s] that they may 

